Demountable brake lining



March 17, 1953 i T. BONKOWSKI DEMOUNTABLE BRAKE LINING 2 SHEET$SHEET 1 TEOF/L L.50NKOM$K/,

INVENTOR.

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March 17, 1953 T. L. BONKOWSKI DEMOUNTABLE BRAKE LINING 2 SHEETS SHEET 2 Filed Sept. 25, 1948 fisoF/L L. BoA/zaws/a,

INVENTOR.

Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE DEMOUNTABLE BRAKE LINING Teofil L. Bonkowski, Los Angeles, Calif. Application September 25, 1948, Serial No. 51,160

3 Claims.

My invention relates to demountable brake linings, that is, to brake linings which may be secured to or removed from a brake shoe without removal of the brake shoe from the vehicle. Included in the objects of my invention are:

First, to provide a demountable brake lining which is particularly simple to install, remove or replace without the use of special tools.

Second, to provide a demountable brake lining which may be so arranged as to fit on a conventional brake shoe without changing or altering in any manner the construction of the brake shoe.

Third, to provide a demountable brake lining .which eliminates the need of rivets and which may be so constructed that wear may proceed through the entire lining before metallic contact with the brake shoe can occur.

Fourth, to provide a demountable brake lining which is preformed to the curvature of the brake shoe and may beso arranged that it is secured against both circumferential and axial displacement.

With the above and other objects in view, as may appear hereinafter, reference is directed to the accompanying drawings in which:

Figure 1 is a substantially diagrammatical view of a vehicle brake showing one form of my demountable lining in position on the brake shoes; Figure 2 is an enlarged view of a brake shoe, the View being taken from the radially inner side thereof and showing the manner in which one form of my demountable lining is secured thereto; Figure 3 is a transverse sectional view taken through 33 of Figure 2;

Figure 4 isa side View of a brake shoe using a, modified form of my demountable lining there- 1;

' Figure Sis a fragmentary view from the radially inner side of the brake shoe shown in Figure 4 Figure 6 is a fragmentary perspective view of the brake shoe and lining shown in Figures 4 and 5, the parts being separated to illustrate the manner in which they are assembled;

Figure 7 is a fragmentary perspective view of a further modified form of my brake lining shown in spaced relation to a brake shoe;

Figure 8 is a fragmentary perspective view of a further modified form of brake shoe with the lining shown in the process of assembly thereon;

Figure 9 is a fragmentary view showing the radially inner side of the brake shoe and lining depicted in Figure 8; and

Figure 10 is a fragmentary transverse sectional view through ll0 of Figure 9.

Reference is first directed to Figures 1, 2 and 3. The structure herein illustrated is preferred for the reason that it may be adapted to use on a conventional brake shoe.

The conventional brake includes a pair of brake shoes A mounted within a brake drum B. The brake shoes are connected at one end by a suitable link C. At the other end a hydraulic cylinder D is interposed between the brake shoes so they may be expanded into contact with the brake drum. Each brake shoe is arcuate in form and T-shaped in cross section.

In the construction shown in Figures 1, 2 and 3 a backing member I is provided which is formed of sheet metal and curved to conform to and overlie the brake shoe. One side of the backing member is folded to form an arcuate stiffening rib and locking channel or lip 2. The channel is adapted to hook over the axially inner side of the brake shoe. The opposite or outer edge of the backing member is provided with a setof tabs 3 which are initially straight as indicated by broken lines in Figure 2 and 3, but which, after placement of the backing member on the brake shoe are adapted to be bent over so as to engage the corresponding axial margin of the brake shoe. The circumferential extremities of the backing member are provided with end lugs 4 which overlie the corresponding extremities or ends of the brake shoe.

The backing member I is covered by a brake lining 5 which is preferably cemented thereto as indicated by '6. Such lining 5 may be a conventional molded lining having the usual substantially rigid, inherently arcuate shape. By this arrangement all rivets or other means which must protrude into the lining are eliminated so that the lining may wear virtually its entire thickness before replacement is necessary or before metalto-metal contact occurs. In addition, the backing member may have transverse ridges and grooves and the brake lining molded accordingly.

My demountable brake lining is employed as follows:

To install the brake lining it is merely necessary to remove the wheel and brake drum and expose the brake shoes, assuming of course that the shoes are not equipped with conventional brake lining. The backing member is then slipped over the brake shoe from the exposed or accessible side thereof with the channel 2 towards the inner axial side of the brake shoe until such channel hooks over and engages the brake shoe. The tabs 3 are then bent over to grip the axially outer or acsheet metal as in the first described case.

material.

cessible side of the brake shoe. To remove, it is merely necessary to bend these tabs 3 to their initial position and unhook the backing member from the brake shoe. It thus will be seen that a minimum amount of work is necessary to install or replace my demountable brake lining and that no special tools are required.

The channel member 2 greatly stiffens the backing member so as to reduce the possibility that the relatively brittle brake lining may be broken or torn loose during handling o shipment, as might be the case if the backing member should flex.

Reference is now directed to Figures 4, 5 and 6.

In this construction an otherwise conventional brake shoe I is modified by providing recesses or notches H at spaced points along theaxially inner and axially outer margins of the brake shoe. A backing plate I2 is provided which is formed of Side lugs I3 are bent radially inwardly fromthe back ing plate l2. The lugs preferably include circumferentiallydirected tongues I4. The backing plate is covered by a lining i5 which is preferably cementedthereto as in the first directed structure.

To employ the structure shown in Figures 4, 5 and 6, it 'is merely necessary to spring the back- 'ing plate over'the brake shoe and guide the'lugs by slitting the backing plateadjacent the lugs 13 maybe bent into the notches l l behind the lugs to prevent-accidental disengagement.

Reference is now directed to Figure 7. This construction is adapted to be employed on the conventional brake shoe A or on the special brake shoe [0. This construction'includes a linin 2 l in which is molded insert strips 22 which are disposed crosswise or axially and terminate at tab ends 23 which protrudetfrom the lining and are adapted to be folded over the margins of the brake shoe in the :manner iofthe tabs .2 and 3 of v the first :described structure. Additional tabs may extend circumferentially from the extremities of the lining 2| to perform the function of the end lugs 4 of-the first described structure.

Reference is now directed to Figures 8, 9 and 10. The structure here shown involves a special brakeshoe 3! which differs from the conventional in that it-is provided with pairs oftapered slots 32. .A molded lining 33 is employed which includes integral tapered bosses 34 adapted to fit the tapered slots 32. The bosses 34-preferably are provid'ed'with small side ribs '35 so as to interlock with the margins ofthe tapered slots'32. At the larger endof one or more tapered'bosses 34 the lining is provided with a keeper opening 36 which receives a keeper plug'31 formed of brake lining The keeper plug is adapted to be inserted in the keeper opening and extends into the tapered slot 32 to prevent withdrawal of the bosses 34. The keeper plug is provided with a cotter pin hole 33 to receive a cotter pin 39, em-

"ployed to prevent removal of the keeper plug.

Assembly of the structure shown in Figures 8,-9 and is as follows:

The molded brake lining 33 is placed over the brake shoe and the bosses 34 are pressed into the slots 32. The lining is then moved circumferentially in the direction of the arrow in Figure 8 until the bosses interlock with the slots, whereupon the keeper plug, or plugs, is inserted and the cotter pin placed to prevent withdrawal of the keeper plug.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. A demountable brake lining for brake shoes of arcuate form comprising: an arcuate sheet metal backing plate having a radius of curvature substantially equal to that of the outer surface of the brake shoe, one margin only of said arcuate backing plate having .a continuous circumferentially extending, radially inwardly directed flange, said flange terminating along itsradiallyfinner edge in a continuous arcuate lip extending away from said'fiange to-form With-said backing plate an arcuate trough, the opposite arcuate margin of said backing plate having a plurality of spaced tabs extending axially away from saidopposite arcuate margin, and a brakelining having a substantially rigid inherently arcuate :shape :cemerited to said backing plate.

2. A demountable brake lining :as setiforth'in clainrLwherein: the circumferential extremities of said backing plate have tabs adapted to be folded over theends of said brakeshoetoresist circumferential displacement :of said backing plate and brake'linin'g.

3. A demountable brake lining as set'forthin claim 1, whereinzsaid .brake shoe .is provided with a series of recesses along :one arcuatemargin to receive said tabs, the circumferential extremities ofsaid recesses cooperating'with the circumferential edges of said tabs to resistcircumferential displacement of said backing plate and brake lining.

'I'EOFIL'L. BONKOWSKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED. STATES PATENTS Number Name Date 1,225,555 Achtmeyer May 8, 1917 1,620,030 Krieg Mar. 8, 1927 1,772,639 Slade Aug. 12 1930 1,856,812 Jirka May 3, 1932 1,903,723 Palmer Apr. 11,1933 1,950,260 Nelson Mar. 6, 1934 2,027,823 Hofiman Jan. 14, 1936 2,153,341 Ruffino Apr. '4, 1939 2,326,300 Kraft Aug. 10, 1943 FOREIGN PATENTS Number Country Date 898,821 France May 8, 1945 372,169 Italy June 19, 1939 

